I love some of their cover art. You just need to be aware that occasionally the translation of classic texts is dated because sometimes they go for cheap, over quality. Other times the translations are up there with the best (I like their Kafka, and Hesse translations).
I've said before, but I prefer Penguin's translations because they're nice to read, but I'll use Oxford for academic research and work, because they're generally more accurate. For example, reading the Brothers Karamazov in Penguin, but researching Thus Spoke Zarathustra in Oxford